• Previous article: 7.6. How important is pitch accent?
• Next article: 7.8. What is yōon?

7.7. What is the difference between a mora and a syllable?

Moras are the rhythmic units of Japanese. The Japanese writing system of kana is based on moras, placing one kana on each mora, with some exceptions with 'softened consonants' like kya, known as yōon. See 7.8. What is yōon?

The difference between moras and syllables is:

• A long vowel is counted as 2 moras.
• Aa is one syllable, but two moras, a-a
• Ou is one syllable, but two moras, o-o
• Ei is one syllable, but two moras, e-e
• A syllabic n (ん) without a following vowel is counted as one mora, and these three are represented as a single n' mora (haneru oto). An is one syllable, but two moras, a-n'. Kankei "relationship" is two syllables, "kan" and "kei", but four moras, ka-n'-ke-e.
• Double consonants (sokuon) are counted as one mora. Thus oppai, "breasts" is two syllables, "op"-"pai", but four moras, o-(p waiting)-pa-i, and ippai is two syllables, "ip"-"pai" but four moras, i-(p waiting)-pa-i.
• The Japanese phonetic system doesn't have any consonant terminated moras except n'. They do exist in practice, like the ending -des' for desu, but we consider it to have (neutral or half) vowel of /u/, and t', d' are considered to be /to/, /do/, respectively.

In changing English words to Japanese, for example 'trumpet' is pronounced torampetto. The moras are to-ra-n'-pe-(sokuon)-to, which makes six, although the original has two syllables, trum-pet. See also 5.1. How do I write an English word in Japanese?

There are also various reasons to consider Tookyoo "Tokyo" and hanbun "half" both to be two-syllable but four-mora words.

Moras are counted as 1-paku, 2-haku, ... using haku (拍) or 1-on, 2-on, ... using on (音).

Acknowledgements

This answer is based on a newsgroup post by muchan.

• Previous article: 7.6. How important is pitch accent?
• Next article: 7.8. What is yōon?

Copyright © 1994-2013 Ben Bullock

If you have questions, corrections, or comments, please contact Ben Bullock or use the discussion forum / Privacy

Book reviews	Convert Japanese numbers	Handwritten kanji recognition	Stroke order diagrams	Convert Japanese units